SGI PCI Digital Audio Board <also known as the RADical Audio board>. The SGI part number for the example shown is 030-1649-001, it appears in an hinv with PCI vendor ID 0x10a9(SGI) and a device ID of 0x0005(RAD Audio):

SGI USB PCI card, SGI part number 9210286: NEC chipset - Slotted for 3.3 and 5V PCI applications. SGI equipped Onyx 350 InfiniteReality and InfinitePerformance systems with this card as an attachment point for USB keyboards and mice. There are some references on TechPubs indicating Orange Micro as the OEM, while "UP205-0525" screened on the PCB returns Adaptec references. It appears in an hinv with a PCI vendor ID of 0x1033 (NEC) PCI device numbers 0x0035(Dual OHCI controllers plus Single EHCI controller) and 0x00e0(USB 2.0 Host Controller).

V6, V8 gfx: X11 support doesn't exist, and likely won't for a very long while. Stan (the IP30 Port Author) recently got console mode running on this card, but from what I understand, this is a rather complex piece of video hardware. Remote X works, however.

Impact gfx: X11 is working

Onboard sound works well enough from what I hear. I tested several MP3s from console via mpg123, and they worked well. A new patch coming out next week (Jul 23-24) will enable support for the optical inputs/outputs for AES (ADAT capabilities will not be supported).

Onboard Scsi works like a charm. It wasn't entirely usable about 3 weeks ago due to reliance on the old qlogicisp driver, but with some very recent fixes to qla1280, it has replaced qlogicisp. I now run a RAID5 array using 3 50G seagate drives on my Octane, and so far, everything works great (and hdparm reports ~17.4MB/s throughput).

Onboard Ethernet works fine too. The IOC3 driver was recently re-written to make IOC3 more of a Bus device with peripherals hanging off of it, which makes IOC3 less of a nightmare device from a coder's standpoint (but not by much).

boot examples

dual boot, idea

It should be possible if you set up IRIX as per normal and leave space on the drive for Linux. Install Linux as per the guide except when you get to set up the PROM. you'll want to leave that as is. Then you'd set up arcload to boot up Linux on demand.